Most, if not all aspects of female reproductive physiology are subject to neural and/or hormonal regulation; however, the interrelationships between peripheral nerves and the endocrines are poorly understood. Several studies have implicated an afferent innervation from the ovary in hypothalamic-hypophyseal function. Although the efferent innervation to the ovary is understood, afferent pathways have not been clarified. We propose to inject horseradish peroxidase into the ovary and determine its localization in sensory ganglia. The ovarian content of catecholamines drops sharply prior to ovulation, and we hypothesize that intraovarian mechanisms regulate them. We propose measurement of ovarian catecholamines and monoamine oxidase (an enzyme which inactivates catecholamines) during different reproductive states, including the preovulatory period. Recent studies on rats in our laboratory have demonstrated that cutting the vagus nerve: (1) interrupts the induction of pseudopregnancy in response to cervical stimulation on the morning of estrus; (2) prevents the nocturnal and diurnal prolactin surges and elevations in serum progesterone, characteristic pf pseudopregnancy; (3) interrupts pregnancy when done on day 3; and (4) inhibits the acute release of FSH and compensatory ovarian hypertrophy in response to unilateral ovariectomy. We propose to determine whether vagotomy in early pregnancy blocks luteal activation by inhibiting the nocturnal and diurnal prolactin surges of early pregnancy. We will also determine whether the effects of vagotomy are acute or chronic and whether the return to "normal" reproductive function is associated with regeneration of the vagus nerve. The acute and chronic effects of vagotomy on LHRH content in ovariectomized, vagotomized rats will also be determined. Lastly, the role of the pelvic splanchnic nerves in parturition will be clarified. When these nerves are cut parturition is blocked in rats. Estradiol, progesterone, 20 Aplha-dihydroprogesterone, relaxin, oxytocin and opristagkabd and F2 Alpha will be quantitated, along with uterine receptors for oxytocin and estrogen in pelvic neurectomized animals. Collectively, the proposed studies should provide a basis for understanding how agents affecting the autonomic nervous system also affect reproductive function.